Building-related health complaints and symptoms are a significant occupational health problem. Elevated concentrations of various types of indoor contaminants - frequently associated with inadequate ventilation, have been implicated as a potential cause. Volatile organic compounds (VOCs), which are mainly emitted from building materials and furnishings, constitute an important class of indoor-air contaminants in non-industrial buildings. Typical building ventilation systems are designed to maintain comfort while controlling carbon dioxide concentrations and odors. Their effectiveness on removing indoor-generated VOCs remains unclear. This proposed research aims at modeling and evaluating the performance of different ventilation systems on VOC removal in indoor environments. Critical parameters of human exposures and thermal comfort will be investigated under conditions of different source configurations, ventilation designs, climate, and load conditions. Computational Fluid Dynamics (CFD) models will elucidate the interactions among these factors including simulated buoyancy sources. Controlled full-scale chamber studies will be conducted to validate the CFD model developed. Reasonable recommendations for the selection of ventilation systems based on detailed model simulations will also be offered. The proposed research is relevant to the following NORA research priority areas: Indoor Environment (10), Exposure Assessment Methods (16), and Intervention Effectiveness Research (18). The research presents an environmental engineering solution to control indoor air pollution in office buildings. Research findings will provide reliable information to assess comfort and indoor air quality, which is needed by engineers and architects for the design of healthier indoor environments. This would help to improve the quality and environmental performance of the work environment.